In a mobile conveying apparatus, for example a transportable grain auger apparatus, it is desirable to provide a means whereby a lengthy elongate conveyor may be folded for storage and transport. Typical grain conveyors incorporate a lengthy auger, comprising an auger tube, auger flighting and drive means for rotating the auger. It can be awkward to transport and store such apparatus. Foldable conveyors, including foldable augers, are known in the prior art. For example, U.S. Pat. No. 3,337,068 (Meharry) discloses an auger arrangement, wherein the main auger flighting and housing is foldable in two parts about a central hinged joint. The respective auger flightings in the first and second parts are keyed together when the auger is unfolded for use to permit the flighting in the first part to rotatably drive the flighting of the second part. One drawback of the arrangement disclosed in this reference is that the operator is required to manually fold the auger, which may be difficult if the auger is heavy or is positioned inaccessibly. As well, two-part folding of the auger may not sufficiently compact the unit for transport or storage. The first drawback has been addressed in the art by providing a power-driven arrangement for folding an auger or other conveyor. For example, U.S. Pat. No. 3,550,793 (Davidow et al.) discloses a folding auger, wherein the folding and unfolding operation is driven by a hydraulic cylinder. A similar arrangement is shown in U.S. Pat. No. 4,427,105 (Hawley et al.).
It is further known to provide conveyors foldable in three or more parts to provide for more compact storage or transport. For example, U.S. Pat. No. 4,659,262 (van Aalst) discloses a pneumatic duct foldable in three parts, and supported by a folding, hydraulically driven exterior frame. Folding of the frame is effected by a separate hydraulic cylinder mounted at each fold.
It is desirable to provide an auger-type conveyor that is foldable in three or more sections into a relatively compact unit, and wherein a single hydraulic cylinder or other motive force effects the folding operation. The use of a single cylinder, rather than a separate cylinder at each joint, reduces the cost and complexity of the device and also permits a coordinated folding operation of the conveyor without the need for controlling and coordinating multiple hydraulic cylinders. Such an operation is possible through the use of tie rods that link adjacent conveyor sections, with a single hydraulic cylinder serving both to drive the folding of adjacent sections and actuate the tie rod or rods.
It is also desirable to provide a conveyor foldable in three or more sections, wherein the folding occurs on intersecting planes. Thus, for example, a proximal and middle conveyor section might fold on a horizontal plane and the distal section fold on a vertical plane. This arrangement can permit a more compact folding of the conveyor, and is particularly useful where the conveyor extends from a large piece of equipment such as a grain vacuum device. In this case, the proximal sections of the conveyor should fold in a vertical plane to permit a section of the conveyor to rest on top of the equipment, while the distal conveyor section is conveniently folded on a horizontal plane, in order that it may lie beside the proximal folded sections of the conveyor.
The terms "proximal" and "distal" used herein are directional references referring to positions close to and distant from, respectively, the attachment point or base of the auger.